|The Axial Volcano
When I first wrote about this volcano the story was more about the technology and the discoveries that were made than the volcano itself. The article was about NeMO, New Millineium Observatory. Three groups of sensors had been placed in and around the volcano way back in 1997. Those sensors were in place and detected the 1998 eruption.
I should explain that the Axial Volcano is a sea mount. A mountain under sea that does not breach the surface. This sea mount is two hundred and fifty miles west of Newport, Oregon and a mile down at the ocean's bottom. The caldera is two miles wide and four miles long. It sits on the Juan de Fuca ridge. That is the spreading ridge between the Pacific plate and what is left of the Juan de Fuca plate. The ridge is pushing the Juan De Fuca plate east under the North American plate.
This year on the annual return trip to the volcano the scientists found that there had been another eruption. What made this unique was that it had been predicted. In a paper published in 2006 it was noted that the sea floor was re-inflating at a rate of six inches a year. That doesn't sound like much, but in a science that measures things at a rate of an inch a year, six inches is a gallop. The prediction was actually: When the sea floor regains the elevation at a level equal to that prior to the 1998 eruption, then the volcano would erupt again.
The sea floor rise, measured by bottom pressure sensors, came up a bit short of the 98 measure. Following the 1998 eruption the sea floor had subsided ten and a half feet . The scientists gave the time for the next eruption as prior to 2014. This year on the annual expedition to the site the area being surveyed looked different. The rest of the expedition was spent recovering the bottom anchored instruments and surveying the area with a remotely operated vehicle (ROV). The initial study has led to the assessment that this eruption was three times larger than the 1998 eruption.
Many of the hot springs/black smokers that had previously existed were no longer there, including the pre-exsisting biological communities. The sea water was murky with what is called floc. Floc is the discharge from the newly formed hot springs. And it is a form of bacteria. It is this bacteria that supports life there in the deep. Tube worms, crabs, moray eels and fish live in and around these hot springs. Life with chemosynthesis, instead of photosynthesis.
This eruption is considered larger than the 98 eruption. The sea floor subsided six feet. However, the lava flow was much larger. What is an eruption without lava? The flow currently is judged to be two miles long (plus or minus), a half mile wide and fifteen feet thick. That is three times the size of the 98 eruption. Not as dramatic as that of Mount Kileuea with its constant pumping of lave to the sea. Nor is it as astounding as the eruptions of Mt St. Helens when the lava was pushed up at the size and rate of a swimming pool per minute. Still a flow of two miles and a thickness of fifteen feet is no small amount.
There is of course more. It can be found at Hatfield Marine Science Center. You can explore under water without any scuba gear.